Youmans G R, Davis T E, Fuller D D
Wishard Memorial Hospital, Indiana University Medical Center, Indianapolis.
Diagn Microbiol Infect Dis. 1993 Feb;16(2):99-104. doi: 10.1016/0732-8893(93)90002-o.
Chemiluminescent DNA probes (AccuProbe, species specific; and FlashTrack, bacterial generic) were used to determine oxacillin resistance in Staphylococcus aureus. Ribosomal RNA was measured at designated intervals in the presence and absence of antibiotic. A total of 48 (AccuProbe assay) and 24 (FlashTrack) S. aureus isolates with known oxacillin susceptibility patterns were inoculated into Bactec 6A bottles both with and without 4 micrograms/ml oxacillin and incubated at 35 degrees C for 4 h. Aliquots were removed at 0 and 4 h, and pellets of bacteria were obtained via selective centrifugation. Probe assay counts (relative light units, RLUs) were performed. Of 21 oxacillin-resistant S. aureus (ORSA) strains, 20 showed a > 5-fold RLU increase during the incubation period (Accu-Probe assay): 25 of 27 oxacillin-susceptible strains demonstrated a < or = 4-fold increase. AccuProbe test sensitivity and specificity were 95% and 92%, respectively. With the generic FlashTrack probe assay, all nine ORSA isolates showed a > or = 4- to 10-fold increase in RLUs, and all 15 oxacillin-susceptible strains showed a < or = 4-fold increase in RLUs during the 4-h incubation. The FlashTrack test sensitivity and specificity were both 100%. Probe assays were completed within 5 h. This study suggests that rapid and reliable determination of oxacillin resistance in S. aureus clinical isolates can be accomplished using commercially available DNA probes.
采用化学发光DNA探针（AccuProbe，种属特异性；以及FlashTrack，细菌通用型）来测定金黄色葡萄球菌对苯唑西林的耐药性。在有和没有抗生素的情况下，于指定时间间隔测量核糖体RNA。将总共48株（AccuProbe检测法）和24株（FlashTrack检测法）已知苯唑西林敏感性模式的金黄色葡萄球菌菌株接种到含和不含4微克/毫升苯唑西林的Bactec 6A瓶中，并在35℃下孵育4小时。在0小时和4小时取出等分试样，通过选择性离心获得细菌沉淀。进行探针检测计数（相对光单位，RLUs）。在21株耐苯唑西林金黄色葡萄球菌（ORSA）菌株中，20株在孵育期间RLU增加了5倍以上（Accu - Probe检测法）；27株苯唑西林敏感菌株中有25株RLU增加≤4倍。AccuProbe检测的敏感性和特异性分别为95%和92%。使用通用的FlashTrack探针检测法，所有9株ORSA分离株在4小时孵育期间RLU增加≥4至10倍，所有15株苯唑西林敏感菌株RLU增加≤4倍。FlashTrack检测的敏感性和特异性均为100%。探针检测在5小时内完成。本研究表明，使用市售DNA探针可快速可靠地测定金黄色葡萄球菌临床分离株对苯唑西林的耐药性。
